1. Field of the Invention
The present invention is directed to a scan circuit (hereinafter “scanning circuit”) that is adaptive to plural kinds of systems different in scanning order by arbitrarily skipping reading of a plurality of data flip flop circuits that do not require the scanning circuit when a coarse system of a scanning means is selected in the scanning circuit which is made up of the plurality of data flip flop circuits that sequentially read an output signal in synchronism with a clock.
2. Description of the Related Art
A conventional scanning circuit that is made up of a plurality of data flip flop circuits that sequentially read an output signal in synchronism with a clock is used as a drive circuit for a sensor IC or a memory. In the case where only arbitrary bit data is intended to be read, it is necessary to sample only data necessary for the external after all of data has been read once (for example, refer to JP 5-167988 A (pp. 7-8, FIG. 9).
Since the conventional scanning circuit is structured as described above, a read rate at the time of reading all of data is fixed because all of data is read. Also, the coarse system of the scanning means cannot be selected, and an external processing IC is required.